Toxin Concentration Research Articles

Unprecedented toxic blooms of Microcystis spp. in 2019 in the Chowan River, North Carolina

The Chowan River flows from southern Virginia through northeastern North Carolina and into the Albemarle Sound, the second largest U.S. estuary. The Chowan, which serves as an important recreational area and provides critical nursery habitat for multiple vulnerable species, has garnered much attention in recent years due to recurrent cyanobacterial harmful algal blooms (cHABs) associated with microcystins (MCs). Here we document unprecedented toxic blooms of Microcystis spp. during summer and fall of 2019 with MC concentrations two to three orders above the recreational guidelines of the Environmental Protection Agency (EPA, 2019). Based on 16S sequencing results in this study and previously published reports, the genus Microcystis emerged as a primary concern within the region. Shifts in assemblage composition, including relative abundance of Microcystis spp. and contributions from potential MC-degraders, linked to overall toxin concentrations and bloom stage. Congeners of varying toxicity, mainly MC-RR and MC-LR, were the most prevalent, corroborating that congeners other than MC-LR should be considered as health risk guidelines are developed. Downstream toxin transport was indicated based on changes in accumulated dissolved MC within the western Albemarle Sound which matched toxin dynamics in the Chowan River. This study provides important novel data on bacterial community composition, MC dynamics, and spatial connectivity for the Chowan River region that can aid monitoring approaches and management strategies for the protection of public health along the Chowan River and within the western Albemarle Sound.

Effects of Temperature, Salinity and CO2 Concentration on Growth and Toxin Production of the Harmful Algal Bloom species Alexandrium pseudogonyaulax (Dinophyceae) from the Danish Limfjord

The marine dinoflagellate Alexandrium pseudogonyaulax is a widely distributed Harmful Algal Bloom (HAB) species that produces the macrocyclic polyketide goniodomin A (GDA). Occurrences in northern European waters are increasing and a spreading of the species along a salinity gradient into the Baltic Sea has been observed. As GDA is suspected to lead to invertebrate mortality, the spreading is of concern for the environment and possibly human health. In order to assess the potential of A. pseudogonyaulax to adapt to the environmental conditions in the Baltic Sea and the risk of future harmful blooms of that species, we quantified the influence of bottom-up factors on the growth and toxin content of three strains of A. pseudogonyaulax from the Danish Limfjord. Specifically, we exposed these strains to salinities ranging from 5 to 50, temperatures in the range of 10 – 30°C and to three different CO2 concentrations of 250, 400 and 1000 µatm. All strains tolerated a broad range of salinities and temperatures, resulting in positive growth rates ranging from 0.06 to 0.33 d-1 between temperatures of 12 and 27°C and between salinities of 10 and 40. The highest cell quotas of GDA were measured at low temperatures. For two strains, GDA amounts were almost unaffected by salinity, while the cell quota of the third strain decreased about 20-fold when salinity increased above 30. Different CO2 concentrations had no effect on growth or GDA production. In summary, these findings show a high ecological tolerance towards a wide range of temperatures and salinities of the Limfjord population of A. pseudogonyaulax, together with distinct intraspecific physiological differences within the population. Our results also suggest that a further spreading into the Baltic Sea might be possible.

Clam Size Explains Some Variability in Paralytic Shellfish Toxin Concentrations in Butter Clams (Saxidomus gigantea) in Southeast Alaska

Harmful algal blooms (HABs) are a reoccurring threat to subsistence and recreational shellfish harvest in Southeast Alaska. Recent Tribally led monitoring programs have enhanced understanding of the environmental drivers and toxicokinetics of shellfish toxins in the region; however, there is considerable variability in shellfish toxins in some species, which cannot be easily explained by seasonal bloom dynamics. Persistent concentrations of paralytic shellfish toxins (PSTs) in homogenized butter clam samples (n > 6, Saxidomus gigantea) have been observed in several communities, and relatively large spikes in concentrations are sometimes seen without Alexandrium observations or increased toxin concentrations in other species. In order to investigate potential sources of variability in PST concentrations from this subsistence species, we assessed individual concentrations of PSTs across a size gradient of butter clams during a period of relatively stable PST concentrations. We found that increasing concentrations of PSTs were significantly associated with larger clams using a log-linear model. We then simulated six clams randomly sampled from three size distributions, and we determined large clams had an outsized probability of contributing a significant proportion of the total toxicity in a six-clam homogenized sample. While our results were obtained during a period of low HAB activity and cannot be extrapolated to periods of intoxication or rapid detoxification, they have significant ramifications for both monitoring programs as well as subsistence and recreational harvesters.

Future of Uremic Toxin Management

During the progression of chronic kidney disease (CKD), the retention of uremic toxins plays a key role in the development of uremic syndrome. Knowledge about the nature and biological impact of uremic toxins has grown exponentially over the past decades. However, the science on reducing the concentration and effects of uremic toxins has not advanced in parallel. Additionally, the focus has remained for too long on dialysis strategies, which only benefit the small fraction of people with CKD who suffer from advanced kidney disease, whereas uremic toxicity effects are only partially prevented. This article reviews recent research on alternative methods to counteract uremic toxicity, emphasizing options that are also beneficial in the earlier stages of CKD, with a focus on both established methods and approaches which are still under investigation or at the experimental stage. We will consequently discuss the preservation of kidney function, the prevention of cardiovascular damage, gastro-intestinal interventions, including diet and biotics, and pharmacologic interventions. In the final part, we also review alternative options for extracorporeal uremic toxin removal. The future will reveal which of these options are valid for further development and evidence-based assessment, hopefully leading to a more sustainable treatment model for CKD than the current one.

Stable Halide Perovskite CsPbBr3 Nanocrystals Assisted by Covalent-Organic Frameworks for Electrochemiluminescence Analysis in an Aqueous Medium.

Lead halide perovskites have garnered attention as promising electrochemiluminescence (ECL) emitters owing to their superior photophysical characteristics. However, their poor water stability severely restricts their application in aqueous media for ECL. In this study, inorganic perovskite CsPbBr3 was assembled in situ in the imine-linked covalent-organic framework (COF-LZU1) as a novel ECL emitter. The expansive surface area and robust hydrophobic architecture of COF-LZU1 not only improved the water stability of CsPbBr3 but also guaranteed its exceptional ECL performance. The novel composite nanoluminescent material was coated onto an indium tin oxide (ITO) electrode via spin-coating and calcination processes to serve as an electrochemiluminescence (ECL) platform. A sensor was developed by combining a DNA hydrogel target-induced release system with a platform using ascorbic acid (AA) as a coreactant and T-2 toxin as the target analyte model. This method achieved a detection limit as low as 3.56 fg·mL-1 and was successfully applied to the analysis of the T-2 toxin content in corn samples. This study offers a novel path for the advancement of perovskite-based ECL emitters and their utilization in aqueous environments within the ECL field.

Effects of Increasing Oral Deoxynivalenol Gavage on Growth Performance, Blood Biochemistry, Metabolism, Histology, and Microbiome in Rats.

Mycotoxin-contaminated feed or food can affect physiological responses and cause illnesses in humans and animals. In this study, we evaluated the effects of deoxynivalenol (DON) toxicity on the growth performance, blood biochemistry, histology, microbiome, and metabolism of rats fed with different toxin concentrations. After 1 week of acclimatization, seven-week-old male rats received 0.9% saline as a control, 0.02 mg/kg DON as T1, and 0.2 mg/kg DON as T2 via oral gavage for 4 weeks. The final body weight of the T2 group was significantly lower than that of the control and T1; however, the average daily gain, feed intake, and feed conversion ratio did not differ. Fibrosis and apoptosis were observed in various tissues as DON concentration increased. Creatinine and alkaline phosphatase levels were significantly lower in the DON-treated group than in the control. Firmicutes and Desulfobacterota phyla dominated the cecum, whereas those in the feces were Proteobacteria and Bacteroidetes. Metabolomic profiling showed phenylalanine, tyrosine, and tryptophan biosynthesis as the most prominent pathways. Overall, our results suggest that low-dose and short-term DON exposure can trigger several adverse effects in rats. Dietary toxicants in rats may explain the physiological effects associated with the metabolism commonly reported in animals.

The spinal consequences of HT-2 toxin and selenium deficiency during bone maturation in mice.

In our investigation, we probed the ramifications of low selenium diets and HT-2 mycotoxin exposure on spinal development and structural fidelity in murine models. A cohort of 48 male mice was segregated into six groups: a control set, a singular low selenium diet group, two cohorts exposed to distinct concentrations of HT-2 toxin (1.6 and 3.2 mg/kg·bw·d), and two assemblies subjected to a confluence of low selenium intake and each designated HT-2 dosage. Across an 8-week investigative period, parameters such as body mass, markers of bone metabolism, and cellular vigor were assiduously monitored. Analytical techniques encompassed biomechanical assessments, X-ray scrutiny, and micro-computed tomography (micro-CT) evaluations. Our results unveiled a dose-dependent diminution in the body mass of mice exclusively exposed to HT-2 toxin, whereas concurrent exposure to both low selenium and HT-2 toxins elicited a synergistic effect. Pertinent shifts were observed in calcium, phosphorus, and vitamin D concentrations, as well as in the operational dynamics of osteoblasts and osteoclasts, aligning with toxin dosage and combined exposure. Variations in biomechanical attributes were also discerned, mirroring the levels of toxin exposure. Micro-CT and X-ray examinations further corroborated the extensive detrimental impact on the cortical and trabecular architecture of the mice's spinal columns. This inquiry elucidates the complex synergistic interactions between low selenium and HT-2 mycotoxin on murine spinal development and integrity under co-exposure conditions. These findings accentuate the exigency of comprehensively understanding the solitary and joint effects of these toxins on osseous health, providing pivotal insights for future toxicological research and public health strategies.

Sea-Air Transfer of Ostreopsis Phycotoxins Is Driven by the Chemical Diversity of the Particulate Fraction in the Surface Microlayer.

Blooms of Ostreopsis cf. ovata pose an emerging health threat, causing respiratory disorders in various coastal regions. This dinoflagellate produce potent phycotoxins named ovatoxins that can be transferred from the seawater to the atmosphere. However, the biotic and abiotic conditions affecting their transfer are still unknown. In this study, we investigate the sea-to-air transfer of O. cf ovata phycotoxins using a process study in an aerosol reference tank (MART) and field observations. The process study exhibited a positive correlation between the phycotoxin content in sea spray aerosol (up to 832.59 ng m-3) and the particulate phycotoxin fraction in the water column and surface microlayer. In contrast, in the natural system, aerosolized phycotoxins were only observed in one out of six air collection (total toxins 0.59 ng m-3) despite optimal wind conditions. In both the process study and the natural system, ovatoxins represented only a minor fraction of the total toxin content, which was comprised of up to 90% liguriatoxins. In seawater, while no solubilized ovatoxins were detected, the concentration in dissolved liguriatoxin-a reached up to 19.07 μg L-1. These results underscore the need for future research on the liguriatoxins, and on their toxicity to establish safe exposure thresholds for beachgoers.

Environmental Drivers of Local Demography and Size Plasticity in Fire Salamanders (Salamandra salamandra).

Conspecific amphibian populations may vary widely in local demography and average body size throughout their geographical range. The environmental drivers of variation may reflect geographical gradients or local habitat quality. Among fire salamander populations (Salamandra salamandra), local demography shows a limited range of variation because high concentrations of skin toxins reduce mortality from predation to a minimum, whereas average adult body size varies significantly over a wide range. This study on four neighboring populations inhabiting the catchments of low-order streams in the upper middle Rhine Valley (Koblenz, Germany) focuses on the identification of local environmental drivers of variation in age and body size. I collected 192 individuals at two localities per stream, measured snout-vent length, clipped a toe for posterior skeletochronological age determination, and released salamanders in situ again. Populations were similar in age distribution. Local habitat quality accounted for a significant proportion of demographic variability, mediated by the impact of landscape-induced mortality risk, including roads and agriculture. Still, the main effect of variation in habitat quality was on adult body size, the result of growth rates of aquatic larvae and terrestrial juveniles. Larvae exposed to non-lethal heavy metal contamination in streams developed into smaller juveniles and adults than clean-water larvae, providing evidence for carry-over effects from one stage to another. The generally small average adult size in the Rhine Valley populations compared to those in other parts of the distribution range indicates the action of a still unidentified environmental driver.

Detection and monitoring of MC-LR and MC-RR in the artifical irrigation ponds at Oltu district

Although it is defining as natural organic pollutant, surface water resources which are frequently exposed to Harmful Algae Blooms (HABs) due to the increasing nutrient loading in recent years, the increase in temperature caused by climate change and the increase in surface run-off caused by extreme rainfall as a result of the risk of the increasing concentrations of algal toxins into drinking water. Although HABs have caused the problem of eutrophication in surface waters especially at hot seasons in the past decades due to the water pollution, increasing surface water temperatures with climate change cause this problem to extended periods out of season and to be permanent for the year. Therefore, studies including the detection and monitoring of algal toxins are gaining importance in order to observe HAB events at their source. As global temperature increases, HAB events have spread to regions that have even cold climates. Consequently, Microcystin-LR (MC-LR) and Microcystin-RR (MC-RR), which are the main indicators of HAB events in surface waters were aimed to detect and monitor at the artificial ponds designed for agriculture and animal husbandry purposes in Oltu District of Erzurum Province which has cold climate, for the first time in this study.Microcystins (MCs) concentrations were measured in the samples taken from ponds in four seasons for one year, by LC-MS/MS and; water temperature and pH values were also determined simultaneously. The relationship between the MC-LR and MC-RR distributions and, the pH and temperature were calculated by Pearson Correlation Coefficient (r).

Potential involvement of connective tissue growth factor in chondrocytes apoptosis of Kashin-Beck disease

BackgroundKashin-Beck disease (KBD) is an endemic osteoarthropathy characterized by excessive chondrocytes apoptosis. T-2 toxin exposure has been proved to be its etiology. Connective tissue growth factor (CTGF) exerts a profound influence on cartilage growth and metabolism. We investigated the potential role of CTGF in KBD development and examined CTGF alterations under T-2 toxin stimulation. MethodsThe levels of CTGF and chondrocyte apoptosis-related markers in cartilage and primary chondrocytes from KBD and control groups were measured using qRT-PCR, Western blotting, immunohistochemistry, and immunofluorescence. We analyzed expression changes of these genes in response to T-2 toxin. Apoptosis rates of chondrocytes induced by T-2 toxin were measured by flow cytometry and TUNEL assay. The active pharmaceutical ingredient targeting CTGF was screened through Comparative Toxicogenomics Database, and molecular docking was performed using AutoDock Tools. ResultsThe CTGF levels in KBD cartilage and chondrocytes were significantly elevated and positively associated with the levels of apoptosis-related genes. T-2 toxin exposure increased CTGF and apoptosis-related gene levels in chondrocytes, with apoptosis rates rising alongside T-2 toxin concentration. Curcumin was identified as targeting CTGF and exhibited effective binding. It could down-regulate CTGF, apoptosis-related genes, such as Cleaved caspase 3 and BAX, and also significantly reduce apoptosis rate in chondrocytes treated with T-2 toxin. ConclusionCTGF plays a crucial role in the development of KBD. Curcumin has shown potential in inhibiting CTGF levels and reducing chondrocyte apoptosis, highlighting its promise as a therapeutic agent for preventing cartilage damage in KBD. Our findings provided valuable insights into the pathogenesis of KBD and could promote the development of novel therapeutic strategies for this debilitating disease.

Pyometra alters uterine aquaporins related with lipopolysaccharide concentrations and antioxidant enzyme activities in bitches

Pyometra is a common life-threatening inflammatory disease with a complex etiopathogenesis that develops during the diestrus stage and can be observed in elderly intact bitches. The present study evaluated five aquaporin (AQP1, AQP2, AQP3, AQP5, and AQP9) transcript abundances and immunolocalization in the uterine tissue, and investigated their relationship with uterine tissue and blood lipopolysaccharide (LPS) concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, and nitric oxide (NO) production in dogs suffering from pyometra. The study sampled 36 client-owned intact bitches from different breeds, of which 24 cases were diagnosed with pyometra. Twelve of these bitches in the diestrus stage that presented for elective ovariohysterectomy were used as the control group. Blood samples were collected into tubes without anticoagulant for serum progesterone, LPS concentration, and antioxidant activities at the time of diagnosis. Bacteriological and tissue samples from the uteri were collected after the ovariohysterectomy. The tissue samples were used to determine antioxidant activity, and hormone and toxin concentrations. Transcript abundance of uterine AQPs were determined by qPCR, and their presence and localization were determined by by immunohistochemistry. For all pyometra samples, the bacteria isolated from the uterine swabs were Escherichia coli. Compared to the control group, AQP1, AQP2, and AQP5 were downregulated more than 2-fold, whereas AQP9 was upregulated nearly 3-fold and AQP3 was upregulated more than 4-fold in the pyometra affected uteri (P<0.05). Uterine AQP1 was moderately negatively correlated with serum LPS concentration (r=-0.568, P<0.01) and tissue NO production (r=-0.407, P<0.05). AQP5 was positively correlated with serum SOD activity (r=0.485, P<0.05) and negatively correlated with serum LPS concentration (r=-0.512, P<0.05). AQP9 was negatively correlated with tissue SOD and serum GPx activity. This is the first study to identify AQP9 transcript abundance and immunolocalization in canine uterine tissue. Uterine AQP1, AQP2, AQP3, AQP5, and AQP9 transcript abundances were altered in spontaneously developed canine pyometra while AQP transcript abundance was negatively related to serum toxin concentration, NO production, and antioxidant enzyme activity. Further studies should be conducted to determine the role of altered abundances of AQPs transcripts in pyometra pathogenesis.

Dietary protein intake and the tubular handling of indoxyl sulfate.

Chronic kidney disease (CKD) patients are advised to limit their protein intake. A high protein diet is known to induce glomerular hyperfiltration, as well as hypertrophy of the remnant kidney, and glomerulosclerosis. Whether the diet causes changes in kidney tubule transport via gut microbiome metabolites is still unknown. We hypothesized that protein intake affects not only the intestinal generation and absorption, but also the kidney disposal of microbial amino acid metabolites. We combined data from animal models and human studies. 5/6th nephrectomy rats were administered a high (HP) or low-protein (LP) diet for 7 weeks. Plasma and urine concentration of the uremic toxins (UTs) indoxyl sulfate (IS), p-cresyl sulfate (PCS), and p-cresyl glucuronide (PCG) were measured. Their fractional excretion (FE) was calculated. The expression of kidney membrane transporters OAT1, OAT3, BCRP, OCT2 and MRP4 was analyzed. Differences in FE of UTs between individuals with higher and lower protein intake in two CKD cohorts were sought. CKD rats on an HP diet showed increased plasma levels of PCS and PCG but not IS compared to rats on a LP diet. Conversely, urinary excretion and FE of IS were higher in the HP CKD group. BCRP, MRP4 and OCT2 were not influenced by the diet. OAT1 and OAT3 were upregulated in the HP CKD group. In two independent cohorts of CKD patients, individuals with a high dietary protein intake showed a significantly higher FE of IS. A HP diet leads to a higher generation and/or absorption of aminoacid-derived UT precursors in CKD rodent models and humans, most likely via gut microbiome modulation. We demonstrate that dietary protein intake modulates transcription and expression of OAT1 and OAT3, corroborating the existence of the remote sensing and signaling hypothesis. Dietary protein intake influences kidney physiology beyond glomerular filtration.

Seasonal nitrogen removal in an outdoor microalgal polyculture at Nordic conditions.

Microalgal solutions to clean waste streams and produce biomass were evaluated in Nordic conditions during winter, spring, and autumn in Southeast Sweden. The study investigated nitrogen (N) removal, biomass quality, and safety by treating industrial leachate water with a polyculture of local microalgae and bacteria in open raceway ponds, supplied with industrial CO2 effluent. Total N (TN) removal was higher in spring (1.5 g-2d-1), due to beneficial light conditions compared to winter and autumn (0.1 and 0.09 g-2d-1). Light, TN, and N species influenced the microalgal community (dominated by Chlorophyta), while the bacterial community remained stable throughout seasons with a large proportion of cyanobacteria. Winter conditions promoted biomass protein (19.6-26.7%) whereas lipids and carbohydrates were highest during spring (11.4-18.4 and 15.4-19.8%). Biomass toxin and metal content were below safety levels for fodder, but due to the potential presence of toxic strains, biofuels or fertilizer could be suitable applications for the algal biomass. PRACTITIONER POINTS: Microalgal removal of nitrogen from leachate water was evaluated in Nordic conditions during winter, spring, and autumn. Total nitrogen removal was highest in spring (1.5 g-2d-1), due to beneficial light conditions for autotrophic growth. Use of local polyculture made the cultivation more stable on a seasonal (light) and short-term (N-species changes) scale. Toxic elements in produced algal biomass were below legal thresholds for upcycling.

INFLUENCE OF MIXOTROPHY ON CELL CYCLE PHASE DURATION AND CORRELATION OF KARLOTOXIN SYNTHESIS WITH LIGHT AND G1 PHASE IN KARLODINIUM VENEFICUM: Influence of mixotrophy on cell cycle and toxicity in Karlodinium veneficum

Karlodinium veneficum forms fish killing blooms in estuaries worldwide. The toxicity of these blooms is variable and thought to be connected to bloom stage and in situ growth rates. Methods for measuring in situ growth rates rely on the assumption that cell cycle progression is phased to the diel photocycle, which is true for phototrophically-growing K. veneficum cultures where G1 phase occurs during light and S and G2 + M phases occur during darkness. However, K. veneficum is a facultative mixotroph that also phagocytizes microalgal prey, and the effects of this mixotrophy on its cell cycle synchrony are unknown. Furthermore, toxicity in laboratory cultures is inversely related to growth rate and is light dependent, suggesting synchrony between the cell cycle (G1 phase) and karlotoxin synthesis. To test this, the cell cycle phase distribution and cellular toxin content for phototrophic and mixotrophic cultures of K. veneficum were monitored hourly for a full diel cycle. The results demonstrated that mixotrophic cultures maintained a synchronized cell cycle, despite increased growth rates. The faster growth rates were attributed to a shortened duration of G1 phase in mixotrophic cultures compared to phototrophic cultures (30.8 ± 9.2 hours vs 69.4 ± 21.5 hours, respectively). Meanwhile, toxin production was observed only during light hours, consistent with synthesis initiating with the photorespiratory byproduct glycolate. Cellular toxin content had a significant positive correlation with the percentage of G1 phase cells and a significant negative correlation with the percentage of S phase cells. These results indicate a clear role in mixotrophy increasing growth rates of K. veneficum and of the diel photocycle in synchronizing the cell and karlotoxin synthetic cycles.

The assessment of the minimum inhibitory concentration of Botulinum toxin on Staphylococcal bacteria isolated from Acne vulgaris and validating its impact through Polymerase Chain Reaction analysis

Acne vulgaris (AV) is an inflammation of pilosebaceous unit which commonly occurs in adolescence. Staphylococcus aureus is also involved in AV pathogenesis. This study included isolating and diagnosing 35 samples of bacteria isolated from acne by the aerobic method and dividing them according to their sensitivity to methicillin,10 samples were used in determining the extent of the effect of different concentrations of Botulinum toxin on bacteria using PCR technology. The results obtained 2.5mg/ml as the MIC for the bactria. Botox treatment at 2.5mg/ml demonstrated molecular effects, causing a lack of PCR binding in selected samples. This suggests a potential disruption in gene transcription or DNA degradation, aligning with international studies showcasing Botox's molecular impact on acne-related Staphylococcus aureus, supporting its role in combination therapy for bacterial control. Botox, renowned for cosmetic use, is also under investigation for medical applications like treating acne. Research suggests that Botox may reduce acne by minimizing sebum production and inhibiting bacteria associated with acne, particularly Staphylococcus aureus. Global studies support these findings, revealing potential applications beyond cosmetics, expanding into acne treatment.

Sodium alumino silicate (SAS) neem nanocomposite – A novel seed storage tool against toxigenic Aspergillus flavus causing deterimental effects on seeds health and quality of rice

Infection of rice grains in the field during harvest and storage by Aspergillus flavus, a toxigenic mold causes significant losses to market acceptability of seeds due to its detrimental effects on seed health and quality parameters. Production of aflatoxin by A. flavus interferes with physiological factors affecting the quality of seeds during storage in addition to nutritional losses to the grains. Chemical seed treatments are generally not recommended during storage due to their adverse effects on seed germination and vigor. Leaves of the neem tree (Azadirachta indica) are well known for antifungal properties against phytopathogenic fungi such as A. flavus. The paper presents the effect of neem leaf extract adsorbed onto sodium alumino-silicate (SAS) nanoparticles against A. flavus in rice seeds during storage. SAS-Neem nanocomposite, a novel unexplored seed storage material against toxigenic A. flavus, was synthesized for augmented antitoxin and seed invigorating potential. The nanocomposite was characterized using an array of microscopic and spectroscopic methods to evaluate the adsorption of neem leaf extract components on SAS nanoparticles. The antifungal mechanism of the nanocomposite was evaluated via scanning electron microscope, phase contrast, and fluorescence microscopy. The toxin analysis of pathogen-inoculated seeds was carried out at monthly intervals for 6 months during storage of two rice varieties, i.e. PR114 and Pusa-Basmati 1121. The results indicated that the nSAS-Neem composite used as seed coating material maintained significantly higher seed germination (86.23 and 81.49%) and minimized seed rot (6.70 and 5.30%, respectively) in the two varieties under study than the control after 6 months of storage. There was a notable decrease in toxin concentration from 20.58 to 11.19 μg/kg and 19.16 to 12.58 μg/kg in seeds of the two varieties i.e. PR114 and Pusa Basmati 1121, respectively. The nano-composite proved effective against toxigenic A. flavus during seed storage of rice without compromising the seed quality parameters.

A probabilistic hazard assessment for cyanobacterial toxins accounting for regional geography and water body trophic status

Under climate change scenarios freshwater eutrophication is expected to increase, and with it the occurrence of cyanobacterial toxin-producing harmful algal blooms. In the current study, microcystin toxin occurrence data from literature sources and a long-term provincial monitoring program were used to conduct a probabilistic hazard assessment for Alberta, Canada. The large temporal and spatial range of data makes Alberta a model system for identifying regional geography and water body trophic status factors driving toxin concentrations. Environmental exposure distributions of microcystin concentrations were plotted and used to identify the likelihood of a given sample exceeding water guideline values as a function of regional geography, total phosphorus and chlorophyll-a concentration. This process identified regions with intensive cultivation and those most prone to water deficits associated with climate change to be most associated with exceedances of regulatory guideline values. Elevated phosphorus and chlorophyll-a concentrations were also drivers of toxin occurrence. This assessment can be used to identify water bodies of greatest risk to human and animal populations from cyanotoxins and thereby inform regulators as to most effective monitoring strategies.

PSIII-27 Blood biochemistry, histology, and metabolomic profiling of contaminated with mycotoxin: A repeated dose oral toxicity study in rats

Abstract Mycotoxins causes diseases and physiological responses in humans and livestock. This study was performed to estimate the effects of binary mixtures mycotoxin {e.g., deoxynivalenol (DON) and fumonisin (FB)] on blood biochemistry, histology, and metabolic profiles in rats fed with different toxin concentrations. Experimental animals were administered by oral gavage with 0.9% saline, DON (1, 5, and 10 mg/kg BW), FB (1, 5, and 10 mg/kg) at 8 wk of age. Histological changes, metabolomic profiling, and blood biochemical analysis were performed Masson’s trichrome stain kit, liquid chromatography mass spectrometry, and VetTest chemistry analyzer, respectively. The final BW of the rats contaminated with mixtures mycotoxin significantly decreased compared with the control group. Biochemistry results and fibrosis were also significantly differentially regulated according to mycotoxin concentrations. Additionally, we observed collagen fibers in the liver and kidney showed blue staining after toxin contamination. For metabolomic profiling, data were analyzed using MetaboAnalyst 4.0. Results were analyzed by multivariate analysis to elucidate the potential compounds. The toxin-treated groups observed discriminating metabolites in the liver and kidney tissue but no differences in ileum. The profiling revealed potential metabolites such as glycine, serine and threonine metabolism. Phosphatidylethanolamine and tryptophan were identified with high sensitivity as candidate biomarkers via variable importance in the projection plot in piglets fed with mycotoxin (FDR &amp;lt; 0.05; P &amp;lt; 0.05). The differently treated groups showed discriminating metabolites in different concentrations. In conclusion, these findings suggest that mycotoxin exposure disturbs histological changes and metabolites. Dietary toxins in rats may better understand the physiological effects consistent with metabolism, which are commonly reported in animals.

Zirconium-based metal-organic framework composites for solid phase extraction of brevetoxin-A from seawater

Red tides are a type of natural marine disaster caused by harmful algae characterized by a high toxicity, wide distribution, and long duration. Since the concentration of algal toxins in seawater increases with the occurrence of red tides, algal toxins detected in seawater could be used to predict the occurrence and evolution of red tides. Brevetoxin-A (BTX-A) is a secondary metabolite produced by the harmful algae Karenia brevis, whose detection in seawater could form the basis of an accurate warning system for incoming red tides. However, due to the inherent complexity of the seawater matrix and the extremely low levels of BTX-A in seawater, the use of instruments for its direct detection is difficult. Therefore, there is an urgent need to develop a sample pretreatment method for the efficient enrichment of BTX-A in seawater. In this study, a metal-organic backbone material (UiO-66) and its composite with silica microspheres (SiO2@UiO-66) were successfully synthesized using the solvothermal method. The prepared SiO2@UiO-66 exhibited good hydrophilicity, water stability, and large specific surface area. Furthermore, it also exhibited hydrogen bonding and electrostatic interactions with BTX-A, had a strong affinity for BTX-A, and was able to efficiently adsorb BTX-A in complex matrices. Therefore, SiO2@UiO-66 showed potential as a novel packing material for the extraction of BTX-A from solid phase extraction columns. Combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a highly sensitive detection method for the determination of BTX-A in marine water was established. The established analytical method had a low detection limit (3.0 pg/mL), a wide linear range (10.0 -200.0 pg/mL), and a good linear relationship (R=0.9992). Combined with the Fujian Province Red Tide Monitoring and Early Warning Information 2021 issued by the Fujian Provincial Oceanic and Fisheries Bureau, the analytical method established herein was successfully applied to analyze and monitor the content of BTX-A in actual seawater samples. This highlights the proposed system's potential for use as an early warning factor in the monitoring of red tides, representing a simple and fast pretreatment methodology for the detection of BTX-A in seawater.